I am the user this post is referring to. My ban has now ended. Allow me to give my perspective.
For one, I regret that I used personal attacks in some of my discussions. Some topics discussed on this website are controversial, and sometimes discussions get heated. Admittedly, this does not excuse my actions. I apologize that some of my discussions got out of hand, but some context certainly needs to be provided.
Your quotations are extremely selective. For instance, in one of our discussions, you were trivializing the deaths and horrid mistreatment of North Koreans by the North Korean regime. Your comment implied that Jewish suffering under the Nazis was somehow "worse" than the suffering of the North Korean people, as though somehow you have the right to make such moral judgements. I would urge you to study the sheer brutality of the North Korean regime. Perhaps this and this are worth reading. Again, it is not something that you ought to trivialize, and a person of Korean ethnicity may well get offended by such comments, just as a Jew might get offended by Holocaust denial/trivialization, or an Armenian might get offended by Armenian genocide denial. This was what motivated my "anti-Semetic" response. Contrary to what your post suggests, my comments did not come out of the blue.
You write that we should not tolerate "personal attacks" and "anti-Semitism" here. I agree that personal attacks should not be tolerated. I have been suspended for a week because of my comments, and I concede that this punishment was deserved. However, we need to be careful with this whole "anti-Semitism" stuff.
I agree that anti-Semitism should not tolerated insofar as users should not be targeted because of their ethnicity (it is important to note that "Zionist" and "Jew" are not synonyms; criticizing the political ideology of Zionism should certainly be allowed). However, the problem here is that what does and does not constitute anti-Semitism is a rather debatable topic. For instance, if we cite scholars such as Kevin MacDonald, who has explored the exceedingly controversial topic of the role of evolutionary psychology in Jewish ethnocentrism, in one of our answers, would that constitute anti-Semitism? Can we talk about the reality of ethnic differences in IQ, which is true? Jews do, on average, have higher verbal IQs than non-Jews. And there is scholarly evidence (namely, by the aforementioned scholar Kevin MacDonald, as well as some Jewish scholars like Israel Shahak) that Jews tend to act in their collective interest as a distinct ethnoreligious group (as opposed to acting in the interest of the country in which they reside). Is this racism? Is this anti-Semitism? I mean, it is not explicitly hateful. This is simply an empirical observation. Where do we draw the line? Or do we simply have a blanket policy that any and all criticism of the Jewish people is unacceptable, thereby implicitly supporting the view that the Jewish people are a perfect people incapable of doing wrong? Your beliefs, Tim, are predicated on the a priori assumption that beliefs commonly regarded as anti-Semitic are necessarily wrong, and therefore we should not even discuss them at all (they are a "thoughtcrime"). I do not believe this is consistent with the goal of having an open website in which people of various viewpoints are allowed to participate. If you only want one set of ideas or political views to be expressed here, then this needs to be made explicitly clear. Perhaps change the name from "politics.stackexchange" to "leftwing.stackexchange".
To reiterate: although we should remain opposed to personal attacks and blatant racial hatred (and, again, I apologize for my excesses), we need to be careful not to censor people with different views. The smart, college educated folk (who principally constitute this site's user base) remain insulated in a sort of left/centre-left bubble. The reality is that right-wing views, including hard-right views like mine, are not fringe or rare. Among the common people, they are the norm. You cannot pretend they don't exist and then act shocked when Brexit happens and Trump is elected.
Last point: if we ban anti-Semitism from this website, then surely we should also ban anti-white bigotry as well? This would include perpetuating the demonization of white men, as is rather common nowadays in modern, leftist intellectual circles. Again, let's be consistent here.